[PATCH v2 3/8] drm/i915/gtt: add gtt mappable plumbing
Ramalingam C
ramalingam.c at intel.com
Fri Dec 3 17:25:14 UTC 2021
On 2021-12-03 at 12:24:21 +0000, Matthew Auld wrote:
> With object clearing/copying we need to be able to modify the PTEs on
> the fly via some batch buffer, which means we need to be able to map the
> paging structures(or at the very least the PT, but being able to also
> map the PD might also be useful at some point) into the GTT. And since
> the paging structures must reside in LMEM on discrete, we need to ensure
> that these objects have correct physical alignment, as per any min page
> restrictions, like on DG2. This is potentially costly, but this should
> be limited to the special migrate_vm, which only needs to a few fixed
> sized windows.
Matt,
Just a thought. instead of classifying whole ppgtt as VM_GTT_MAPPABLE
and rounding up the pt size to min_page_size,
could we just add size of pt as parameter into i915_vm_alloc_pt_stash
and alloc_pt, which can be used for vm->alloc_pt_dma() instead of
I915_GTT_PAGE_SIZE_4K.
But PT for a smem entries also needs to be 64k aligned to be mapped into
the GTT right? So no advantage of having the pt_stash level physical
alignment..
Any thoughts on this line?
Ram
>
> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Cc: Ramalingam C <ramalingam.c at intel.com>
> ---
> drivers/gpu/drm/i915/gem/i915_gem_context.c | 4 ++--
> drivers/gpu/drm/i915/gem/selftests/huge_pages.c | 2 +-
> drivers/gpu/drm/i915/gt/gen6_ppgtt.c | 2 +-
> drivers/gpu/drm/i915/gt/gen8_ppgtt.c | 3 ++-
> drivers/gpu/drm/i915/gt/gen8_ppgtt.h | 1 +
> drivers/gpu/drm/i915/gt/intel_ggtt.c | 2 +-
> drivers/gpu/drm/i915/gt/intel_gt.c | 2 +-
> drivers/gpu/drm/i915/gt/intel_gtt.c | 7 +++++++
> drivers/gpu/drm/i915/gt/intel_gtt.h | 9 +++++++++
> drivers/gpu/drm/i915/gt/intel_migrate.c | 4 +++-
> drivers/gpu/drm/i915/gt/intel_ppgtt.c | 17 ++++++++++++-----
> drivers/gpu/drm/i915/gt/selftest_hangcheck.c | 2 +-
> drivers/gpu/drm/i915/gvt/scheduler.c | 2 +-
> drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 4 ++--
> 14 files changed, 44 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index ebd775cb1661..b394954726b0 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -1559,7 +1559,7 @@ i915_gem_create_context(struct drm_i915_private *i915,
> } else if (HAS_FULL_PPGTT(i915)) {
> struct i915_ppgtt *ppgtt;
>
> - ppgtt = i915_ppgtt_create(&i915->gt, 0);
> + ppgtt = i915_ppgtt_create(&i915->gt, 0, 0);
> if (IS_ERR(ppgtt)) {
> drm_dbg(&i915->drm, "PPGTT setup failed (%ld)\n",
> PTR_ERR(ppgtt));
> @@ -1742,7 +1742,7 @@ int i915_gem_vm_create_ioctl(struct drm_device *dev, void *data,
> if (args->flags)
> return -EINVAL;
>
> - ppgtt = i915_ppgtt_create(&i915->gt, 0);
> + ppgtt = i915_ppgtt_create(&i915->gt, 0, 0);
> if (IS_ERR(ppgtt))
> return PTR_ERR(ppgtt);
>
> diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> index bd8dc1a28022..c1b86c7a4754 100644
> --- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> +++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
> @@ -1764,7 +1764,7 @@ int i915_gem_huge_page_mock_selftests(void)
> mkwrite_device_info(dev_priv)->ppgtt_type = INTEL_PPGTT_FULL;
> mkwrite_device_info(dev_priv)->ppgtt_size = 48;
>
> - ppgtt = i915_ppgtt_create(&dev_priv->gt, 0);
> + ppgtt = i915_ppgtt_create(&dev_priv->gt, 0, 0);
> if (IS_ERR(ppgtt)) {
> err = PTR_ERR(ppgtt);
> goto out_unlock;
> diff --git a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
> index c0d149f04949..778472e563aa 100644
> --- a/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
> +++ b/drivers/gpu/drm/i915/gt/gen6_ppgtt.c
> @@ -443,7 +443,7 @@ struct i915_ppgtt *gen6_ppgtt_create(struct intel_gt *gt)
>
> mutex_init(&ppgtt->flush);
>
> - ppgtt_init(&ppgtt->base, gt, 0);
> + ppgtt_init(&ppgtt->base, gt, 0, 0);
> ppgtt->base.vm.pd_shift = ilog2(SZ_4K * SZ_4K / sizeof(gen6_pte_t));
> ppgtt->base.vm.top = 1;
>
> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> index 312b2267bf87..dfca803b4ff1 100644
> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
> @@ -912,6 +912,7 @@ gen8_alloc_top_pd(struct i915_address_space *vm)
> *
> */
> struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt,
> + unsigned long vm_flags,
> unsigned long lmem_pt_obj_flags)
> {
> struct i915_ppgtt *ppgtt;
> @@ -921,7 +922,7 @@ struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt,
> if (!ppgtt)
> return ERR_PTR(-ENOMEM);
>
> - ppgtt_init(ppgtt, gt, lmem_pt_obj_flags);
> + ppgtt_init(ppgtt, gt, vm_flags, lmem_pt_obj_flags);
> ppgtt->vm.top = i915_vm_is_4lvl(&ppgtt->vm) ? 3 : 2;
> ppgtt->vm.pd_shift = ilog2(SZ_4K * SZ_4K / sizeof(gen8_pte_t));
>
> diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.h b/drivers/gpu/drm/i915/gt/gen8_ppgtt.h
> index f541d19264b4..c0af12593576 100644
> --- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.h
> +++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.h
> @@ -13,6 +13,7 @@ struct intel_gt;
> enum i915_cache_level;
>
> struct i915_ppgtt *gen8_ppgtt_create(struct intel_gt *gt,
> + unsigned long vm_flags,
> unsigned long lmem_pt_obj_flags);
>
> u64 gen8_ggtt_pte_encode(dma_addr_t addr,
> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> index 47f88f031749..938af60fd32f 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> @@ -661,7 +661,7 @@ static int init_aliasing_ppgtt(struct i915_ggtt *ggtt)
> struct i915_ppgtt *ppgtt;
> int err;
>
> - ppgtt = i915_ppgtt_create(ggtt->vm.gt, 0);
> + ppgtt = i915_ppgtt_create(ggtt->vm.gt, 0, 0);
> if (IS_ERR(ppgtt))
> return PTR_ERR(ppgtt);
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
> index 510cda6a163f..991a514a1dc3 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
> @@ -484,7 +484,7 @@ static void intel_gt_fini_scratch(struct intel_gt *gt)
> static struct i915_address_space *kernel_vm(struct intel_gt *gt)
> {
> if (INTEL_PPGTT(gt->i915) > INTEL_PPGTT_ALIASING)
> - return &i915_ppgtt_create(gt, I915_BO_ALLOC_PM_EARLY)->vm;
> + return &i915_ppgtt_create(gt, 0, I915_BO_ALLOC_PM_EARLY)->vm;
> else
> return i915_vm_get(>->ggtt->vm);
> }
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
> index 5447615fc6f3..d9bf53dc1d85 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
> @@ -18,6 +18,13 @@ struct drm_i915_gem_object *alloc_pt_lmem(struct i915_address_space *vm, int sz)
> {
> struct drm_i915_gem_object *obj;
>
> + if (vm->vm_flags & I915_VM_GTT_MAPPABLE) {
> + struct intel_memory_region *mr =
> + vm->i915->mm.regions[INTEL_REGION_LMEM];
> +
> + sz = max_t(int, sz, mr->min_page_size);
> + }
> +
> /*
> * To avoid severe over-allocation when dealing with min_page_size
> * restrictions, we override that behaviour here by allowing an object
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
> index cbc0b5266cb4..eee97b46a1f9 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
> @@ -266,6 +266,13 @@ struct i915_address_space {
> u8 pd_shift;
> u8 scratch_order;
>
> +/*
> + * Paging structures are going to accessed via the GTT itself, and therefore
> + * might need special alignment.
> + */
> +#define I915_VM_GTT_MAPPABLE BIT(0)
> + unsigned long vm_flags;
> +
> /* Flags used when creating page-table objects for this vm */
> unsigned long lmem_pt_obj_flags;
>
> @@ -543,6 +550,7 @@ i915_page_dir_dma_addr(const struct i915_ppgtt *ppgtt, const unsigned int n)
> }
>
> void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
> + unsigned long vm_flags,
> unsigned long lmem_pt_obj_flags);
>
> int i915_ggtt_probe_hw(struct drm_i915_private *i915);
> @@ -562,6 +570,7 @@ static inline bool i915_ggtt_has_aperture(const struct i915_ggtt *ggtt)
> int i915_ppgtt_init_hw(struct intel_gt *gt);
>
> struct i915_ppgtt *i915_ppgtt_create(struct intel_gt *gt,
> + unsigned long vm_flags,
> unsigned long lmem_pt_obj_flags);
>
> void i915_ggtt_suspend_vm(struct i915_address_space *vm);
> diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c
> index 2d3188a398dd..d553b76b1168 100644
> --- a/drivers/gpu/drm/i915/gt/intel_migrate.c
> +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c
> @@ -78,7 +78,9 @@ static struct i915_address_space *migrate_vm(struct intel_gt *gt)
> * TODO: Add support for huge LMEM PTEs
> */
>
> - vm = i915_ppgtt_create(gt, I915_BO_ALLOC_PM_EARLY);
> + vm = i915_ppgtt_create(gt,
> + I915_VM_GTT_MAPPABLE,
> + I915_BO_ALLOC_PM_EARLY);
> if (IS_ERR(vm))
> return ERR_CAST(vm);
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_ppgtt.c b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
> index b8238f5bc8b1..1218024dfd57 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ppgtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
> @@ -156,20 +156,25 @@ int i915_ppgtt_init_hw(struct intel_gt *gt)
> }
>
> static struct i915_ppgtt *
> -__ppgtt_create(struct intel_gt *gt, unsigned long lmem_pt_obj_flags)
> +__ppgtt_create(struct intel_gt *gt,
> + unsigned long vm_flags,
> + unsigned long lmem_pt_obj_flags)
> {
> - if (GRAPHICS_VER(gt->i915) < 8)
> + if (GRAPHICS_VER(gt->i915) < 8) {
> + WARN_ON_ONCE(vm_flags);
> return gen6_ppgtt_create(gt);
> - else
> - return gen8_ppgtt_create(gt, lmem_pt_obj_flags);
> + } else {
> + return gen8_ppgtt_create(gt, vm_flags, lmem_pt_obj_flags);
> + }
> }
>
> struct i915_ppgtt *i915_ppgtt_create(struct intel_gt *gt,
> + unsigned long vm_flags,
> unsigned long lmem_pt_obj_flags)
> {
> struct i915_ppgtt *ppgtt;
>
> - ppgtt = __ppgtt_create(gt, lmem_pt_obj_flags);
> + ppgtt = __ppgtt_create(gt, vm_flags, lmem_pt_obj_flags);
> if (IS_ERR(ppgtt))
> return ppgtt;
>
> @@ -301,6 +306,7 @@ int ppgtt_set_pages(struct i915_vma *vma)
> }
>
> void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
> + unsigned long vm_flags,
> unsigned long lmem_pt_obj_flags)
> {
> struct drm_i915_private *i915 = gt->i915;
> @@ -309,6 +315,7 @@ void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
> ppgtt->vm.i915 = i915;
> ppgtt->vm.dma = i915->drm.dev;
> ppgtt->vm.total = BIT_ULL(INTEL_INFO(i915)->ppgtt_size);
> + ppgtt->vm.vm_flags = vm_flags;
> ppgtt->vm.lmem_pt_obj_flags = lmem_pt_obj_flags;
>
> dma_resv_init(&ppgtt->vm._resv);
> diff --git a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
> index e5ad4d5a91c0..8c299189e9cb 100644
> --- a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
> +++ b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
> @@ -1600,7 +1600,7 @@ static int igt_reset_evict_ppgtt(void *arg)
> if (INTEL_PPGTT(gt->i915) < INTEL_PPGTT_FULL)
> return 0;
>
> - ppgtt = i915_ppgtt_create(gt, 0);
> + ppgtt = i915_ppgtt_create(gt, 0, 0);
> if (IS_ERR(ppgtt))
> return PTR_ERR(ppgtt);
>
> diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
> index 6c804102528b..d726eee3aba5 100644
> --- a/drivers/gpu/drm/i915/gvt/scheduler.c
> +++ b/drivers/gpu/drm/i915/gvt/scheduler.c
> @@ -1386,7 +1386,7 @@ int intel_vgpu_setup_submission(struct intel_vgpu *vgpu)
> enum intel_engine_id i;
> int ret;
>
> - ppgtt = i915_ppgtt_create(&i915->gt, I915_BO_ALLOC_PM_EARLY);
> + ppgtt = i915_ppgtt_create(&i915->gt, 0, I915_BO_ALLOC_PM_EARLY);
> if (IS_ERR(ppgtt))
> return PTR_ERR(ppgtt);
>
> diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
> index fdb4bf88293b..3bcd2bb85d10 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
> @@ -155,7 +155,7 @@ static int igt_ppgtt_alloc(void *arg)
> if (!HAS_PPGTT(dev_priv))
> return 0;
>
> - ppgtt = i915_ppgtt_create(&dev_priv->gt, 0);
> + ppgtt = i915_ppgtt_create(&dev_priv->gt, 0, 0);
> if (IS_ERR(ppgtt))
> return PTR_ERR(ppgtt);
>
> @@ -1083,7 +1083,7 @@ static int exercise_ppgtt(struct drm_i915_private *dev_priv,
> if (IS_ERR(file))
> return PTR_ERR(file);
>
> - ppgtt = i915_ppgtt_create(&dev_priv->gt, 0);
> + ppgtt = i915_ppgtt_create(&dev_priv->gt, 0, 0);
> if (IS_ERR(ppgtt)) {
> err = PTR_ERR(ppgtt);
> goto out_free;
> --
> 2.31.1
>
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